Visibility (uv) data is delivered for both the spectral lines and continuum.

The format for each spectral line uv data file in a MASSES dataverse is:
targetname].[configuration].[linename].[tracknumber].uvfits

The format for the continuum uv data in a MASSES dataverse is: 
[targetname].[configuration].cont[wavelength].[sideband].[tracknumber].uvfits

In the first MASSES data release (Stephens et al. 2018), the SMA configuration is in the subcompact (sub) array. The delivered spectral lines are 12CO21, 13CO21, C18O21, and N2DP. High velocity CO (highvelCO) is delivered for ASIC data. The continuum is at 1.3 mm, and is delivered separately for the lower and upper sidebands (lsb and usb, respectively). 

For Per-emb-59, there is a single track taken with the ASIC correlator: 151102

To import uvfits files into miriad, the "fits" task should be used. "op=uvin" and "options=varwt" must be specified. We show an example for CO(2-1) below:
fits in=Per59.sub.12CO21.151102.uvfits out=Per59.sub.12CO21.151102.miriad.uv op=uvin options=varwt

To import into casa, the task importuvfits should be used:
importuvfits(fitsfile="Per59.sub.12CO21.151102.uvfits",vis="Per59.sub.12CO21.151102.casa.uv")
Rest frequencies for each spectral line need to be specified in casa to show proper velocities.
